Groudine 1998.

Methods	Randomized, placebo‐controlled trial. No information provided on random sequence generation and allocation concealment. Participants and outcome assessors were blinded. Anaesthesiologists were unblinded. This study examined whether many of the beneficial effects on bowel function seen with epidural lidocaine are also present when the drug is given parenterally in patients undergoing radical retropubic prostatectomy. The study was conducted in the USA from May 1995 to August 1996.
Participants	Number assessed for eligibility: N/A Number randomized: 40 → 20:20 Number analysed: 18:20 Inclusion criteria Male patients undergoing radical retropubic prostatectomy, ASA I to II. Exclusion criteria Preexisting disorder of the gastrointestinal tract; used enemas, opioids, or anticholinergic medication chronically; or were ASA physical status III or more. Baseline details Experimental group (n = 18) Mean age (years): 64.4 (mean age of all experimental and control patients) M = 100%, F = 0% Mean weight (kg): N/A Mean ASA: 2.2 Duration of surgery (min): N/A Main surgical procedure: radical retropubic prostatectomy Control group (n = 20) Mean age (years): 64.4 (mean age of all experimental and control patients) M = 100%, F = 0% Mean weight (kg): N/A Mean ASA: 2.3 Duration of surgery (min): N/A Main surgical procedure: radical retropubic prostatectomy
Interventions	Experimental group (18 patients) Before induction of general anaesthesia, patients received a bolus of intravenous lidocaine 1.5 mg/kg followed by a continuous infusion of lidocaine 1.5 mg/kg/hr until the patients arrived in PACU. The infusion was terminated 60 min after skin closure. Control group (20 patients) Control patients received an equal volume of saline.
Outcomes	Dichotomous Surgical complication (deep vein thrombosis) Adverse events (postoperative fever, blood culture required, perioperative mortality) Continuous First bowel movement (hrs) First flatus (hrs) Hospital stay (days) Total pain score (VAS 0 to 100) Opioid consumption (morphine, mg), PACU and ward Ketorolac consumption (mg)
Notes	Only male patients Small trial sample size (< 200 patients) No sample size calculation reported Exclusion criteria were reported as ASA > II; however, patients were included with ASA III Medication "Ketorolac (30 mg IV) was initiated for all patients in the PACU unless there was a contraindication (history of peptic ulcer disease, renal disease, or concerns about postoperative haemostasis) and continued (15 mg IV) every 6 hrs if needed for pain control. Morphine was used for breakthrough pain and for those patients not receiving ketorolac." Anaesthesia The anaesthesia regime was not standardized ("flexibility in opioid use"). Funding No funding mentioned
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "…a number from 1 to 40 was randomly drawn. Even‐numbered patients received lidocaine. Odd‐numbered patients were assigned to the control group." Insufficient information about the sequence generation process provided.
Allocation concealment (selection bias)	Unclear risk	No statement on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "the nursing staff, surgeons, and patients were all blinded."; "…anaesthesiologists were not blinded and were not involved in any of the data collection…"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "pain scores and inquiries about first flatus and bowel movements were all made by a nurse blinded only to the patient´s lidocaine status."
Incomplete outcome data (attrition bias) All outcomes	High risk	Dropout rate (experimental/control): 10%:0% Quote: "two patients from the lidocaine group were excluded from analysis. One patient withdrew his consent before induction. The other patient had multiple surgical complications….The remaining 38 patients completed the study." The reason for missing data (due to surgical complications) is likely to have an impact on relevant outcomes.
Selective reporting (reporting bias)	Unclear risk	There is no reference to a trial registry and no published study protocol.
Other bias	Low risk	The study appears to be free of other sources of bias.